Calculate Exterior
Materials Instantly
Skip the spreadsheets and guesswork. Get precise siding square takeoffs, gutter slope elevations, downspout counts, and soffit ventilation calibrated for real job sites.
Featured Exterior Calculators
Siding Calculator
Calculate total siding squares, cartons, panels, and trim accessories for rectangular walls and gables with opening deductions.
Gutter Slope Calculator
Determine the exact drop in fractional inches, slope percentage, and intermediate chalk line marks for single or split gutter runs.
Vinyl Siding Calculator
Determine vinyl siding cartons, specific profile exposures (Double 4", 4.5", 5", Single 7"), J-channel, and corner posts.
Downspout Calculator
Calculate the required number of downspouts, profile sizing (2x3" vs 3x4"), spacing analysis, and wall offset elbows.
Hardie Plank Siding Calculator
Calculate James Hardie fiber cement plank counts, exposure reveals, joint flashing tabs, blind nails, and corner boards.
Soffit Vent Calculator
Calculate required Net Free Vent Area (NFVA) for attic ventilation using the IRC 1:300 rule, with balanced intake and exhaust sizing.
Dedicated Siding, Gutter, Downspout & Roof Edge Calculators
Siding Cost & Labor Calculator
Estimate total material costs, tear-off expenses, and contractor installation labor rates across vinyl, fiber cement, and wood siding.
Siding Waste Factor Estimator
Calculate precision scrap allowances for complex gable peaks, dormers, window cutouts, and diagonal architectural walls.
Gutter Parts & Hardware Calculator
Estimate seamless gutter sections, hidden screw hangers, inside/outside miter corners, end caps, and sealant tubes.
SMACNA Gutter Sizing Calculator
Size gutter trough width and profile based on roof catchment area, pitch factor, and maximum 10-year local rainfall intensity.
Gutter Water Volume & Flow Rate
Calculate peak storm runoff flow in GPM, trough storage capacity, and Manning equation velocity for residential eaves.
Soffit Panel & Channel Calculator
Calculate 12-ft soffit panel yields, F-channel perimeter tracks, and J-channel trim for closed or open rafter overhangs.
Fascia Board & Wrap Calculator
Determine 1x6/1x8 lumber lengths, aluminum fascia trim coil footage, and overlap waste for complete roof edge protection.
Why Field Pros Use ExteriorCalc
Engineered to eliminate costly siding shortages, standing gutter water, and job site guesswork.
Built-in Waste Allowances
Real jobs aren't flat planes. We automatically calculate recommended safety buffers for 45° angle cuts, gable rakes, opening deductions, and lap overlaps.
Standard Trade Units
Order in squares, full 2.00 sq cartons, 10-ft gutter sticks, coil rolls, and IRC net free vent square inches. Material takeoffs in the exact units suppliers stock.
Zero Ads or Popups
No video popups or newsletter modals blocking your screen while standing on a ladder or at the supply counter. Fast, reliable, and distraction-free.
Calculator Guides & Field Notes
How to Calculate How Much Siding You Need (Step-by-Step)
A complete contractor-grade walkthrough on measuring rectangular walls, gable peaks, opening deductions, and ordering squares.
How Many Squares of Siding Do I Need? Siding Squares Explained
Learn what a siding square is, why construction uses squares instead of individual panels, and how to calculate exact carton requirements.
How to Calculate Gutter Slope & Pitch (The 1/4" Per 10-Foot Rule)
Detailed instructions on measuring gutter pitch, calculating elevation drop in fractional inches, and installing slope across long eave runs.
More Trade Tools Coming Soon
We are actively expanding our exterior trade library with new tools for standing seam metal roofing, stone veneer, and window wrap flashings.
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